In recent years, Over The Top Video (OTT-V) has become the mainstream of streaming services on the Internet. For example, Moving Picture Experts Group-Dynamic Adaptive Streaming over Hypertext Transfer Protocol (HTTP) (MPEG-DASH) (hereinafter, also referred to as DASH) has started to spread as the basic technology of OTT-V.
In DASH, for example, Media Presentation Description (MPD) serving as metadata that includes attribute information for optimally selecting streams with different characteristics from the same source is notified to a client that receives streams by a server that delivers streams, and the client uses the MPD, by which network environment adaptive streaming is implemented (see, for example, Non-Patent Document 1).
Specifically, in DASH, a server prepares a plurality of streams with different image qualities, different image sizes, etc., as being of the same content, according to a delivery path communication environment, client's capabilities or state, etc.
On the other hand, a client adaptively selects a stream that can be received by the client and that is suited for client's capabilities (decoding capability, etc.) among the plurality of streams prepared by the server, and receives and reproduces the stream.
In DASH, in order that the client can adaptively select and receive a stream, metadata which is called MPD and used for content reproduction control is delivered to the client from the server.
The MPD describes, for example, a Uniform Resource Locator (URL) serving as an address of a segment (media data such as Audio/Video/Subtitle) into which content is divided. The client transmits an http request to a (web) server serving as a content delivery source, on the basis of the URL, etc., described in the MPD, and receives and reproduces a segment that is unicast-delivered by the server in response to the http request.